Optical vortices or light beams with non-zero angular momenta are interesting not only because of their underlying physics, but also because of their potential applications. Potential areas of application include biology, nanotechnology, and communications.
Conventionally used methods of generating beams having a high angular momentum are complicated and require optical setups utilizing holograms, modulating Fabri-Perot cavities, or special microstructures. As a result, generation of beams with orbital momentum up to and exceeding 104 h per photon, though in principle possible, is not easily achievable experimentally. Thus far it has been reported that the highest orbital angular momenta of photons are approximately 25 h and 30 h, and beams with angular momenta of up to 300 h have been demonstrated.
Accordingly, there continues to exist a need for devices and methods that can generate high angular momentum optical beams that are simple to manufacture and easy to implement.